Rebound check



Jan. 5 1926.

N. F.-M NAUGHT REBOUND CHECK Filed. Dec. 29, 1923 Patented Jan. 5, 1926.

UNITED STATES PATENT OFFICE.

NORRIS F. Mo'NAUGI-IT, OF CHICAGO, ILLINOIS.

REBOUND CHECK.

Application filed December 29, 1923. Serial No. 683,347.

To all whom it may concern:

Belt known that I, NORRIS F. MCNAUGHT, a! citizen of the United States,residing at Ch cago, in the county-of Cook and State of Illinois, haveinvented certain new and use ful Im" *ov'einents in Rebound Checks, ofwhich tlie following is a specification.

Thls invention has to do with certain improvements in connection withshock absorbers and like devices; more particularly it is concerned withdevices for absorbing a largeportion of the energy of the recoil ofvehicle axles and springs when passing over uneven surfaces.

he construction herein illustrated and particularly described isintended for use especially with that type of device in which a suitableform of strap is connected at one end to the axle or vehicle spring, andat the other end to a retracting spring which takes up the slack of thestrap when the vehicle spring is compressed. Still more particularly thepresent invention has to do with improvements in devices of theforegoing type which are so arranged that the strap passes in contactwith a friction surface which it engages with a larger amount ofpressure and resultant friction on the recoil of the vehicle spring thanon the initial impact thereof.

In the foregoing type of device the efiectiveness of the deviceforabsorbing the energy of the recoil dep'endslargely upon the amount offrictional contact established between the strap and the surface whichit engages during the recoil; since themain purpose of the checkingspring is to take up the slack of the strap during the compression ofthe vehicle spring and to oppose the withdrawal ofthe strap during therecoil in such a way as to increase the effectiveness of the friction.

The main object of the present invention is to provide, in devices ofthis character, means supplemental to the strap and checking spring, forincreasing the frictional engagenient of the strap with the frictionsurface during the recoil. In thisconncction, a further object is toprovide an adjustment whereby the amount of this supplemental action maybe easilyadjusted. by the mechanic without having to disassemble oropen'up the check itself, and without having to re move the device orany portion thereof from the vehicle.

A further object in connection with the foregoing is to provide suitableconvenient indicating devices which may be readily observed by themechanic to guide him in makingthe foregoing adjustment-s.

A further object in connection with the foregoing is to so arrange andestablish this supplemental friction generating device that it will workin perfect harmony and cooperation with the friction surface of thedevice itself so as to produce a maximum of absorbing action.

Other objects and uses of the invention will appear from a detaileddescription of the same, which consists in the features of constructionand combinations of parts hereinafter-described and claimed.

In the drawing:

Fig. 1 shows a face view of a device em bodying the features of thepresent invention with the cover plate removed so as to betterillustrate the interior construction;

Fig. 2 sh ws a vertical section through the device, taken substantiallyon the line 2-2 of Fig. 1, looking in the direction of the arrows, thecover plate being in place in Fig. 2, but shown in section;

Fig. 3 shows an end view of the cam block of Figs. 1 and 2;

Fig. a shows a longitudinal section on the line 4-4 of Fig. 3, lookingin the direction of the arrows; and

Fig. 5 is a fragmentary inverted face view of the shell at the pointwhere the opening for the strap is formed.

Referring first to the construction illustrated in the drawing, thedevice includes a base plate 7 intended for direct attachment to aconvenient portion of the vehicle chassis, such as one of the frame sidebars. attachment is conveniently made by a bolt passing through the hole8 of the device. This hole is locatedwell over towards one end of thedevice, since the balance of force is such that this can be done andretain the device securely in place by the use of a single bolt.

Adjacent to the base plate 7 is journalled a drum 9 upon a stud l0reaching out from the base plate. A coiled spring 11 is placed withinthe drum and has one end connected to the drum and the other end to astation curved form and preferably lies along the This upper edgeportion of the device. ,'A bracket 13 may be secured to one end of theflange 1-2 by a series of rivets 1 1, said bracket reaching over farenough to establish a supplemental bearing for the stud 10 upon whichthe drum is journaled.

A strap 15 of suitable fabric or special composition has its inner end16 secured to the drum. In the normal position this strap encircles themajor portion of the face of the drum, and then passes over the curvedflange 12. The free end 17 of the strap passes away from the flange 12and downwardly in a practically vertical direction for suitableattachment to the vehicle axle or spring.

\Vhen the vehicle spring is compressed, the pull on the strap is reducedand the spring 11 winds up the drum so as to take up the slack and keepthe strap taut. On the recoil the pull on the end 17 must besufficiently large to overcome the resistance of the strap passing overthe flange 12 against the retracting force of the drum spring. Theresult is that the force necessary to unwind the strap is much largerthan the force of the spring 11 itself, and a substantial amount ofenergy is dissipated in the form of heat generated by the friction ofthe strap passing over the flange.

According to my present invention I fur ther increase the frictionalengagement of the strap on the flange during recoil by the use of anelement which causes a deflection or sharp turn in the direction of thestrap at or adjacent to the position of the flange 12. In theconstruction illustrated this takes the form of a pin or block 18 havinga rounded and preferably circular surface 19, said pin being located insuch a position as to deflect the strap in a rather sharp manner asindicated at 20 in Fig. 1. This deflection is caused at a point betweenthe drum and the adjacent end of the flange 12, and, consequently,serves to largely increase the force necessary to withdraw the free end17 of the strap during recoil.

As shown. the block 18 is circular in form and is provided witheccentric studs 21 and 22 on its ends. These studs are journaled in thebase plate 7 and in the bracket 13 res'iectively. By turning the devicethe amount of interference with the travel of the strap can be adjustedowing to the eccentricity of the mounting of the block 18. This turningis easily accomplished by placing a suitable tool on the projecting head23 of the block which has the flattened surfaces 2% and 25. An arrow 26may be placed on this projecting head for comparison with u'iarltings 27on the outside face of the device, so that the amount of interferencecan be adjusted. v

A set scre 28 is placed in the base plate 7 at a pro-per point forengagement with the stud 21, so that the device can be locked in theadjusted position.

Ordinarily a shell 31 is placed over the absorber, the game beingprovided with an opening at the point where the strap passes through. Inorder to prevent the strap from catching on its edges, the shell may beoutwardly flared, as shown at 33 in Fig. 5, this being a desirableexpedient inview of occasional friction between the strap and the shellwhich results from lateral movements of the stiap as an incident to itsuse.

lVhilc I have herein shown and described only certain embodiments of thefeatures of the present invention, still I do not intend to limit myselfto the same except as I may do so in the claims.

I claim:

1. In a rebound check. the combination with a spring retracted drum, astrap coiled on the drum and having one end secured thereto, astationary curved friction plate adjacent to the drum, the. strappassing from the drum over the friction plate and having its free endadapted for attachment to a vehicle axle, whereby when said free end isreleased the strap is wound on the drum by the operation of the springand when the free end is withdrawn the strap is unwound from the drmnand pulled over the friction plate against the tension of the spring tothereby absorb the energy of the rebound of the axle. of means forregulating the friction engagement of the strap on the friction plateduring the rebound comprising a pin in contact with the outer face ofthe strap at a point adjacent to its travel over the friction plate, aneccentric mounting therefor, suitable markings designating the angularposition of the pin, and means for locking the pin in adjusted position,substantially as described.

2. In a rebound check, the combination with a spring retracted drum, astrap coiled on the drum and having one end secured thereto. astationary friction plate adjacent: to the drum, the strap passing fromthe lrum over the friction plate and having its free end adapted forattzu-hmcnt to a vehicle axle. whereby when said free end is releasedthe strap is wound on the drum by the operation of the spring and whenthe free end iswithdrawn the strap is unwound from the drum and pulledover the friction plate a ainst the tension of the spring to therebyabsorb the energy of the rebound of the axle, of means for regulatingthe friction engagement of the strap on the friction plate during therebound comprising a pin in contact with the strap at a point adjacent;to its travel over the friction plate, an eccentric mounting therefor.and means for locking the pin in adjusted position, substantially asdescribed.

3.1111 a rebound check. the combination with a spring retracted drum, astrap coiled on the drum and havingone end secured thereto, a stationaryfriction plate adjacent to the drum, the strap passing from the drumover the friction plate and having its free end adapted for attachmentto'a vehicle axle, whereby when said free end is released the strap iswound on the drum by the operation of the spring and when the free endis withdrawn the strap is unwound from the drum and pulled over thefriction plate against the tension of the spring to thereby absorb theenergy of the rebound of the axle, of means for regulating the frictionengagement of the strap on the friction plate during the reboundcomprising a pin in contact with the strap at a point adjacent to itstravel over the friction plate, and an eccentric mounting therefor,substantially as described.

4. In a rebound check, the combination with a spring retracted drum, astrap coiled on the drum and having one end secured thereto, astationary friction plate adjacent to the drum, the strap passing fromthe drum over the friction plate and having its free end adapted forattachment to a vehicle axle, whereby when said free end is released thestrap is wound on the drum by the operation of the spring and when thefree end is withdrawn the strap is unwound from the drum and pulled overthe friction plate against the tension of the spring to thereby absorbthe energy of, the rebound of the axle, and means for regulating thefriction engagement of the strap on the friction plate during therebound comprising a pin in contact withthe strap at a point adjacent toits travel over the friction plate and in advance of the terminal edgeof the friction plate, substantially as described.

5. The combination with two spring connected parts of a. rebound checkmounted on the one part, a strap connected at one end to the other part,a spring actuated drum rotatably carried by the check and having aconnection with the other strap end, and a L duplex friction meansassociated with the strap comprising a curved wall over which the strapis extended, the wall having in spaced relation to the drum one endaround which the strap is bent, and an adjustable device between thewall end and the drum adapted to be projected toward the strap todeflect the same whereby its bend around the wall may be varied,substantially as described.

6. The combination with two spring connected parts of a rebound checkmounted on the one part, a spring actuated rotatable drum carried by thecheck, a curved wall associated with the drum with one end spacedtherefrom, a strap connected with the drum and extended therefrom overthe curved wall to the other part for connection therewith, and aneccentric device carried by the check adjacent the strap between thedrum and said wall end adapted for movement toward and from the strapwhereby the latter may be deflected, substantially as described.

7. The combination with two spring connected parts of a rebound checkmounted on the one part and including a base plate from which upstands acurved friction wall and a stud in spaced relation thereto, a drummounted for rotation about the stud, spring means associated with thedrum for rotatin the same in one direction, a strap connecte with thedrum and passing therefrom over the friction wall to connect with theother part, a bracket connecting the wall with the stud, and a rotatableblock having an eccentric mounting between the base plate and bracketand extended in proximity to the strap intermediately of the drum andwall, the block being adapted to deflect the strap in its passage towardthe wall, substantially as described.

8. The combination with two spring connected parts of a rebound checkmounted on the one part, the check including in its structure a baseplate whereon is carried its several components, a connection from thecheck to the other part comprising a flexible strap adapted for movementrelative to certain of the check components. and a housing removablyattached to the base plate having in one of its walls an opening throughwhich the strap is passed, the housing walls adj acent the opening andon two edges at right angles to each other being flared away from thestrap whereby to provide rounded edges for occasional engagementtherewith and to thereby eliminate sharp edges fraying the belt edges,substantially as described.

9. The combination with two spring connected parts, of a rebound checkmounted on the one part and having a strap extended therefrom to connectwith the other part, and a housing for the rebound check removablyassociated therewith having in one of its walls a slot through which thestrap'is laterally receivable and freely movable, the walls of thehousing slot immediately adja cent to the edge of the strap being flaredoutwardly from the strap whereby to present a rounded edge foroccasional engage ment therewith to thereby eliminate a sharp edgefraying the belt, substantially as described.

NORRIS F. MGNAUGHT.

